1. Field of the Invention
The present invention relates to a waterproof power window device, and more particularly to a power window device and a control device used therefor which, in the event that an automobile becomes submerged in water for some reason, allows the door windows to be opened in a sure manner by operating a window opening switch.
2. Description of the Related Art
In the event that an automobile is submerged in water, power window devices generally used for automobiles are such that the window-opening switch and window-closing switch are submerged, and thus the contact points of the switches are flooded and consequently an electrically insulated state can hardly be maintained between the points, resulting in the windows initially being moved in an uninstructed and unpredictable manner since the open electrical points begin conducting via the relatively small resistance therebetween, and further, operating the window-opening switch does not open the window in a sure manner.
FIG. 13 is a circuit diagram illustrating an example of the circuit configuration of the principle components of such a known power window device.
As shown in FIG. 13, the power window device is comprised of a window-closing switch 31, a window-closing relay 32 and the contact point 32C thereof, a window-opening switch 33, a window-closing relay 34 and the contact point 34C thereof, an automatic window-opening switch 36, a window-opening/closing motor 37, a controlling integrated circuit (hereafter referred to simply as an "IC"), and an onboard power source 39.
Further, the window-closing switch 31 and the window-closing relay 32 are serially connected between the onboard power source 39 and a ground, and the window-opening switch 33 and the window-opening relay 34 are serially connected therebetween. The contact point A of the window-closing switch 31 and the window-closing relay 32 is connected to the terminals P and S of the controlling IC, and the contact point B of the window-opening switch 33 and the window-opening relay 34 is connected to the terminals Q and T of the controlling IC. The automatic window-closing switch 35 has one end connected to the contact point A and the other connected to terminal R of the controlling IC 38, and the automatic window-opening switch 36 has one end connected to the contact point B and the other connected to terminal R of the controlling IC 38. The contact point 32C of the window-closing relay 32 is arranged so that the movable point is connected to one end of the window-opening/closing motor 37, one fixed point is connected to the onboard power source 39, and the other fixed point is connected to the ground. The contact point 34C of the window-opening relay 34 is arranged so that the movable point is connected to the other end of the window-opening/closing motor 37, one fixed point is connected to the onboard power source 39, and the other fixed point is connected to the ground. The terminal U of the controlling IC 38 is connected to the onboard power source 39.
The power window device configured as described above generally operates as described next.
In the event that the driver or the like operates the window-closing switch 31, the contact point thereof closes, and the window-closing relay 32 is driven by the onboard power source 39. At this time, the contact point 32C of the window-closing relay 32 is switched over, the window-opening/closing motor 37 rotates in one direction, whereby the window moves in the direction of being closed. When operation of the window-closing switch 31 ceases, the contact point thereof opens, rotation of the window-opening/closing motor 37 stops, and the window stops. On the other hand, in the event that the window-opening switch 33 is operated, the contact point thereof closes, and the window-opening relay 34 is driven by the onboard power source 39. At this time, the contact point 34C of the window-opening relay 34 is switched over, the window-opening/closing motor 37 rotates in the other direction, whereby the window moves in the direction of being opened. When operation of the window-opening switch 33 ceases, the contact point thereof opens, rotation of the window-opening/closing motor 37 stops, and the window stops.
In the event that the driver or the like operates the automatic window-closing switch 35, the contact point thereof closes, and the window-closing switch 31 is also operated at the same time such that the contact point thereof closes as well. Due to the closing of this window-closing switch 31, the window-closing relay 32 is driven by the onboard power source 39, the window-opening/closing motor 37 rotates in one direction in the same manner as the case in which the aforementioned window-closing switch 31 is operated, whereby the window moves in the direction of being closed. Also, closing both the contact point for the window-closing switch 31 and the contact point for the automatic window-closing switch 35 supplies voltage from the contact point A to both terminals P and R of the controlling IC 38, and the voltage of the onboard power source 39 is latched and output to the terminal S of the controlling IC 38 in response to the voltage supplied, thereby supplying the voltage of the onboard power source 39 to the window-closing relay 32. Consequently, even in the event that operation of the automatic window-closing switch 35 is ceased so that the contact point thereof is opened, and at the same time operation of the window-closing switch 31 is ceased so that the contact point thereof is opened, the output voltage is latched to the terminal S, so the window-closing relay 32 continues to be driven, the window-opening/closing motor 37 continues to be driven in the one direction, and hence the window continues to be driven in the direction of closing. This driving of the window in the direction of closing continues until the window is fully closed.
In the same way, in the event that the automatic window-opening switch 36 is operated, the window-opening/closing motor 37 rotates in the other direction, whereby the window moves in the direction of being opened. Also, the voltage of the onboard power source 39 is latched and output to the terminal T of the controlling IC 38, so the window-opening relay 34 continues to be driven, the window-opening/closing motor 37 continues to be driven in the other direction, and hence the window continues to be driven in the direction of opening. This driving of the window in the direction of opening continues until the window is fully opened.
Now, in the event that the automobile is submerged in water for some reason, the arrangement of the above-described known power window device is such that when the window-closing switch 31 or the window-opening switch 33 is flooded, leakage resistance 31R and 33R of relatively small resistance are connected between the switches 31 and 33 owing to the water, and even through the points for the window-closing switch 31 and the window-opening switch 33 are open the output voltage of the onboard power source is applied to the window-closing relay 32 and the window-opening relay 34 via the leakage resistance 31R and 33R, meaning that the window-closing relay 32 and the window-opening relay 34 are driven in an unpredictable manner regardless of the intentions of the passengers. Consequently, even in the event that the driver of the automobile or another person attempts to open the window by operating the window-opening switch 33 to drive the window-opening relay, if the window-closing relay is being driven by the leakage resistance 31R, the window opening/closing motor 37 is not driven, and the window will not open. To summarize, known power window devices are problematic in that in the event the automobile is submerged and the power window device is flooded, normal window operating cannot be carried out any more.